Intravision/reactos
1
0
Fork 0
mirror of https://github.com/reactos/reactos.git synced 2024-12-28 10:04:49 +00:00
Code Issues Projects Releases Packages Wiki Activity

[FAST486]

Browse source 
Implement FRNDINT.


svn path=/trunk/; revision=66170
This commit is contained in:
Aleksandar Andrejevic 2015-02-05 01:03:09 +00:00
parent 63773511d0
commit af6093b4a5
1 changed files with 93 additions and 148 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

241
reactos/lib/fast486/fpu.c
View file

@ -34,59 +34,24 @@
/* 0.00 */
static const FAST486_FPU_DATA_REG FpuZero = {0ULL, 0, FALSE};
// {
// .Sign = FALSE,
// .Exponent = 0,
// .Mantissa = 0ULL
// };
/* 1.00 */
static const FAST486_FPU_DATA_REG FpuOne = {0x8000000000000000ULL, FPU_REAL10_BIAS, FALSE};
// {
// .Sign = FALSE,
// .Exponent = FPU_REAL10_BIAS,
// .Mantissa = 0x8000000000000000ULL
// };
/* Pi */
static const FAST486_FPU_DATA_REG FpuPi = {0xC90FDAA22168C234ULL, FPU_REAL10_BIAS + 1, FALSE};
// {
// .Sign = FALSE,
// .Exponent = FPU_REAL10_BIAS + 1,
// .Mantissa = 0xC90FDAA22168C234ULL
// };
/* lb(10) */
static const FAST486_FPU_DATA_REG FpuL2Ten = {0xD49A784BCD1D8AFEULL, FPU_REAL10_BIAS + 1, FALSE};
// {
// .Sign = FALSE,
// .Exponent = FPU_REAL10_BIAS + 1,
// .Mantissa = 0xD49A784BCD1D8AFEULL
// };
/* lb(e) */
static const FAST486_FPU_DATA_REG FpuL2E = {0xB8AA3B295C17F0BBULL, FPU_REAL10_BIAS, FALSE};
// {
// .Sign = FALSE,
// .Exponent = FPU_REAL10_BIAS,
// .Mantissa = 0xB8AA3B295C17F0BBULL
// };
/* lg(2) */
static const FAST486_FPU_DATA_REG FpuLgTwo = {0x9A209A84FBCFF798ULL, FPU_REAL10_BIAS - 2, FALSE};
// {
// .Sign = FALSE,
// .Exponent = FPU_REAL10_BIAS - 2,
// .Mantissa = 0x9A209A84FBCFF798ULL
// };
/* ln(2) */
static const FAST486_FPU_DATA_REG FpuLnTwo = {0xB17217F7D1CF79ABULL, FPU_REAL10_BIAS - 1, FALSE};
// {
// .Sign = FALSE,
// .Exponent = FPU_REAL10_BIAS - 1,
// .Mantissa = 0xB17217F7D1CF79ABULL
// };
/* PRIVATE FUNCTIONS **********************************************************/
@ -200,6 +165,52 @@ UnsignedDivMod128(ULONGLONG DividendLow,
return ValueLow;
}
static inline VOID FASTCALL
Fast486FpuRound(PFAST486_STATE State,
PULONGLONG Result,
BOOLEAN Sign,
ULONGLONG Remainder,
INT RemainderHighBit)
{
switch (State->FpuControl.Rc)
{
case FPU_ROUND_NEAREST:
{
/* Check if the highest bit of the remainder is set */
if (Remainder & (1ULL << RemainderHighBit))
{
(*Result)++;
/* Check if all the other bits are clear */
if (!(Remainder & ((1ULL << RemainderHighBit) - 1)))
{
/* Round to even */
*Result &= ~1;
}
}
break;
}
case FPU_ROUND_DOWN:
{
if ((Remainder != 0ULL) && Sign) (*Result)++;
break;
}
case FPU_ROUND_UP:
{
if ((Remainder != 0ULL) && !Sign) (*Result)++;
break;
}
default:
{
/* Leave it truncated */
}
}
}
static inline VOID FASTCALL
Fast486FpuFromInteger(PFAST486_STATE State,
LONGLONG Value,
@ -265,43 +276,8 @@ Fast486FpuToInteger(PFAST486_STATE State,
/* The result must be positive here */
ASSERT(*Result >= 0LL);
switch (State->FpuControl.Rc)
{
case FPU_ROUND_NEAREST:
{
/* Check if the highest bit of the remainder is set */
if (Remainder & (1 << (Bits - 1)))
{
(*Result)++;
/* Check if all the other bits are clear */
if (!(Remainder & ((1 << (Bits - 1)) - 1)))
{
/* Round to even */
*Result &= ~1;
}
}
break;
}
case FPU_ROUND_DOWN:
{
if ((Remainder != 0ULL) && Value->Sign) (*Result)++;
break;
}
case FPU_ROUND_UP:
{
if ((Remainder != 0ULL) && !Value->Sign) (*Result)++;
break;
}
default:
{
/* Leave it truncated */
}
}
/* Perform rounding */
Fast486FpuRound(State, (PULONGLONG)Result, Value->Sign, Remainder, Bits - 1);
if (Value->Sign) *Result = -*Result;
return TRUE;
@ -335,6 +311,7 @@ Fast486FpuToSingleReal(PFAST486_STATE State,
{
ULONGLONG Remainder;
SHORT UnbiasedExp = (SHORT)Value->Exponent - FPU_REAL10_BIAS;
ULONGLONG Result64;
if (FPU_IS_ZERO(Value))
{
@ -392,43 +369,10 @@ Fast486FpuToSingleReal(PFAST486_STATE State,
/* Calculate the remainder */
Remainder = Value->Mantissa & ((1ULL << 40) - 1);
switch (State->FpuControl.Rc)
{
case FPU_ROUND_NEAREST:
{
/* Check if the highest bit of the remainder is set */
if (Remainder & (1ULL << 39))
{
(*Result)++;
/* Check if all the other bits are clear */
if (!(Remainder & ((1ULL << 39) - 1)))
{
/* Round to even */
*Result &= ~1;
}
}
break;
}
case FPU_ROUND_DOWN:
{
if ((Remainder != 0ULL) && Value->Sign) (*Result)++;
break;
}
case FPU_ROUND_UP:
{
if ((Remainder != 0ULL) && !Value->Sign) (*Result)++;
break;
}
default:
{
/* Leave it truncated */
}
}
/* Perform rounding */
Result64 = (ULONGLONG)*Result;
Fast486FpuRound(State, &Result64, Value->Sign, Remainder, 39);
*Result = (ULONG)Result64;
/* Store the biased exponent */
*Result |= (ULONG)(UnbiasedExp + FPU_REAL4_BIAS) << 23;
@ -524,43 +468,8 @@ Fast486FpuToDoubleReal(PFAST486_STATE State,
/* Calculate the remainder */
Remainder = Value->Mantissa & ((1 << 11) - 1);
switch (State->FpuControl.Rc)
{
case FPU_ROUND_NEAREST:
{
/* Check if the highest bit of the remainder is set */
if (Remainder & (1 << 10))
{
(*Result)++;
/* Check if all the other bits are clear */
if (!(Remainder & ((1 << 10) - 1)))
{
/* Round to even */
*Result &= ~1;
}
}
break;
}
case FPU_ROUND_DOWN:
{
if ((Remainder != 0ULL) && Value->Sign) (*Result)++;
break;
}
case FPU_ROUND_UP:
{
if ((Remainder != 0ULL) && !Value->Sign) (*Result)++;
break;
}
default:
{
/* Leave it truncated */
}
}
/* Perform rounding */
Fast486FpuRound(State, Result, Value->Sign, Remainder, 10);
/* Store the biased exponent */
*Result |= (ULONGLONG)(UnbiasedExp + FPU_REAL8_BIAS) << 52;
@ -1628,8 +1537,44 @@ FAST486_OPCODE_HANDLER(Fast486FpuOpcodeD9)
/* FRNDINT */
case 0x3C:
{
// TODO: NOT IMPLEMENTED
UNIMPLEMENTED;
INT Bits;
ULONGLONG Result = 0ULL;
ULONGLONG Remainder;
if (FPU_GET_TAG(0) == FPU_TAG_EMPTY)
{
State->FpuStatus.Ie = TRUE;
if (!State->FpuControl.Im) Fast486FpuException(State);
break;
}
if (!FPU_IS_NORMALIZED(&FPU_ST(0)))
{
State->FpuStatus.De = TRUE;
if (!State->FpuControl.Dm)
{
Fast486FpuException(State);
break;
}
}
Bits = min(max(0, (INT)FPU_ST(0).Exponent - FPU_REAL10_BIAS + 1), 64);
if (Bits == 64) break;
if (Bits)
{
Result = FPU_ST(0).Mantissa >> (64 - Bits);
Remainder = FPU_ST(0).Mantissa & ((1 << (64 - Bits)) - 1);
}
else Remainder = FPU_ST(0).Mantissa;
/* Perform the rounding */
Fast486FpuRound(State, &Result, FPU_ST(0).Sign, Remainder, 63 - Bits);
State->FpuStatus.Pe = TRUE;
if (!State->FpuControl.Pm) Fast486FpuException(State);
break;
}